Comments: How many brownie combinations can you make with chocolate, butter, eggs, flour, cocoa, vanilla, and a few nuts? Hundreds, it turns out. There are such fine distinctions between so many of these recipes, you really will have to make many of them to find out how they're different. Chances are, most readers will choose one of the two or three recipes they try and stick with it.
There are dozens of "standard" brownies, as well as fruit-laden, coffee-enhanced, white-chocolate-based, etc., etc., as well as a host of recipes for brownie pies, cookies, bars, ice creams, sorbets, sauces, frostings and icings. There are probably 6,314,696 combinations of brownie, nuts, fruits, toppings, glazes, etc. in the pages of this book. That should satisfy any and all brownie cravings.
It's a little odd to have so many recipes ask for both semisweet and bittersweet chocolate, when the author really doesn't distinguish between them in her chocolate glossary and in the marketplace, there is also no clear distinction. Whatever you find, though, will probably produce delightful results.